Carcass characteristics, meat quality
traits, and sensory attributes were evaluated in latefinishing
barrows and gilts, weighing between 100 to
130 kg of BW, fed 0, 5, or 7.4 mg/kg of ractopamine
hydrochloride (RAC) for the final 21 to 28 d before
slaughter. Carcass data were collected from carcasses
from barrows and gilts (n = 168), and all primal cuts
from the right sides of these carcasses were fabricated
to calculate primal yields as a percentage of the HCW.
Subjective (National Pork Producers Council and Japanese)
color, firmness, and marbling scores were determined
on the LM of each loin and the semimembranosus
muscle (SM) of the ham, whereas the moisture,
extractable lipid, Warner-Bratzler shear force (WBSF),
and trained sensory evaluations (juiciness, tenderness,
and pork flavor) were measured on the LM samples
only. Gilts produced heavier (P < 0.05) HCW than barrows, whereas feeding RAC increased (P < 0.05) HCW over pigs fed diets devoid of RAC. Carcasses from gilts also had greater (P < 0.02) primal cut and lean cut (P < 0.01) yields than barrows, and dietary inclusion of 5 mg/kg of RAC increased (P < 0.05) total boneless cut and lean cut yields when compared with carcass from pigs fed 0 or 7.4 mg/kg of RAC. Warner-Bratzler shear forces values were greater (P < 0.05) in the LM of gilts than barrows, but only juiciness scores were greater (P < 0.03) in LM chops from barrows than gilts. The LM from barrows had greater intramuscular lipid (P < 0.001) than the LM from gilts, and even though the LM from pigs fed 5 mg/kg of RAC had greater (P < 0.04) WBSF values than the LM from pigs fed 0 or 7.4 mg/kg of RAC, including RAC in the late-finishing diets for 21 or 28 d did not affect sensory panel rating or percentages of moisture and intramuscular lipid. In summary, addition of RAC in the late-finishing diet improved carcass and primal cut yields when it was fed at 5 and 7.4 mg/kg without altering pork quality traits regardless of whether RAC was fed for 21 or 28 d.